On 8/18/2019 4:57 PM, Roberto Sassu wrote:
> The LSM hooks audit_rule_known() and audit_rule_match() define 1 as
> result for successful operation. However, the security_ functions use
> call_int_hook() which stops iterating over LSMs if the result is not
> zero.
>
> Introduce call_int_hook_and(), so that the final result returned by the
> security_ functions is 1 if all LSMs return 1.
I don't think this is what you want. You want an audit record
generated if any of the security modules want one, not only if
all of the security modules want one.
>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> ---
> security/security.c | 19 +++++++++++++++++--
> 1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/security/security.c b/security/security.c
> index cbee0b7915d5..ff1736ee3410 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -634,6 +634,20 @@ static void __init lsm_early_task(struct task_struct *task)
> RC; \
> })
>
> +#define call_int_hook_and(FUNC, IRC, ...) ({ \
> + int RC = IRC; \
> + do { \
> + struct security_hook_list *P; \
> + \
> + hlist_for_each_entry(P, &security_hook_heads.FUNC, list) { \
> + RC = P->hook.FUNC(__VA_ARGS__); \
> + if (!RC) \
> + break; \
> + } \
> + } while (0); \
> + RC; \
> +})
> +
> /* Security operations */
>
> int security_binder_set_context_mgr(struct task_struct *mgr)
> @@ -2339,7 +2353,7 @@ int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
>
> int security_audit_rule_known(struct audit_krule *krule)
> {
> - return call_int_hook(audit_rule_known, 0, krule);
> + return call_int_hook_and(audit_rule_known, 0, krule);
> }
>
> void security_audit_rule_free(void *lsmrule)
> @@ -2349,7 +2363,8 @@ void security_audit_rule_free(void *lsmrule)
>
> int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
> {
> - return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
> + return call_int_hook_and(audit_rule_match, 0, secid, field, op,
> + lsmrule);
> }
> #endif /* CONFIG_AUDIT */
>
